With the development of display technology, Gate Driver on Array (GOA for short) technology is widely used. GOA technology directly integrates a gate driving circuit of a display panel on an array substrate to replace an external driving chip. However, in GOA technology, a gate of a transistor of a pull-down sub-circuit is influenced by a high level bias voltage for a long time, which causes a threshold voltage of the transistor of the pull-down sub-circuit to be shifted, thereby affecting the performance of the display panel.